There has been put into practical use a virtual computer system in which plural logical partitions (hereinafter, referred to as LPARs) are established on a physical computer and OSs (operating systems) are allowed to operate on the respective LPARs, thereby allowing the plural OSs unique to the respective LPARs to operate.
There are two I/O processing mode-one is an emulation mode in which a hypervisor converts I/O instructions issued by an OS into instructions interpretable by a physical I/O device, and the other is an I/O pass-through mode in which I/O instructions issued by an OS are directly executed by a physical I/O device.
In addition, as a recent type of virtual computer system, a virtual computer system in which a logical FC (Fibre Channel) port is assigned to each LPAR in the I/O pass-through mode has been used under an SAN (Storage Area Network) environment including a RAID apparatus. The I/O pass-through mode is a mode in which an I/O is directly issued from the logical FC port of each LPAR to the SAN.
In a computer system to realize booting under the SAN environment, in order to protect data of LUs (logical units), in which OSs are installed, in a memory device of a RAID apparatus and the like, a security function by which an access is permitted only from the respective computers is realized by the memory device. The security function generally utilizes a method in which, by using unique IDs (World Wide Names) assigned to the FC ports mounted to the respective computers, the logical units having the OSs installed are associated with the unique IDs (World Wide Names) assigned to the FC ports provided for the computers, and an FC port having an unique ID (World Wide Name) is permitted to access only a logical unit associated with the unique ID. Further, there are some cases in which the IDs (World Wide Names) unique to the apparatuses are recorded in software including OSs.
In the computer system to perform booting under the SAN environment, the unique IDs (World Wide Names) assigned to the FC ports of a currently-used computer are different from those assigned to the FC ports of a standby computer. Accordingly, when an actually-used computer is migrated to a standby computer, software images including OSs cannot be used as they are, and it is necessary to change the setting of the security function on the memory device side by SAN management software or a system administrator. The setting change is required not only between the physical computers such as the currently-used computer and the standby computer, but also between virtual computer systems in each of which logical FC ports are respectively assigned to LPARs in the I/O pass-through mode.
About migration processing of an LPAR, Japanese Unexamined Patent Application Publication No. 2010-33404 discloses a technique in which, in the case where a virtual computer operating on a real computer is migrated onto another real computer, a management unit stops the source virtual computer from operating, defines a destination virtual computer on the another real computer, changes configuration information concerning the source virtual computer and configuration information concerning the destination virtual computer while the destination virtual computer is kept stopped from starting, and after the configuration information concerning both virtual computers are changed, the destination virtual computer is allowed to start.